Reciprocating motor system



Aug 927 c. s. WEYANDT RECIPRQCATING MOTOR SYSTEM Filed July 26, 1922 2 Shoots-Shoot 2 WITNESb INVENTOR.

ATTORNEY Patented Aug. 2, 1927. V

UNITED STATES 1,637,717 PATENT OFFICE.

CARL B. WEY ANDT, OI PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO CF-NTBAL ELEC- TRIO TOOL COMPANY, 01' PITTSBURGH, PENNSYLVANIA, A CORPORATION 01 PENN- mvnrru.

BECIPBDCATIN 'G MOTOR SYSTEI.

Application filed m as, a. Serial in. 577,719.

My invention relates to reciprocating motor systems, and particularly to the operation of reci rocating motors, including those utilized or striking blows ,to tools,

such as drills, riveters and the like.

In accordance with my invention, there are selected, by asymmetrical electrical conduction, that is, by electric valve action,

from a source of alternating current a plurality of series of uni-directional current impulses, and the impulses of the diiferent series are utilized to produce magnetic fluxes flux,ior reciprocating a magnetizable member', such as a reciprocating core or vibratory armature.

For this purpose there may be utilized a plurality of magnetic field-producing windings traversed respectively by the impulses of the different series transmitted through asymmetrical electrical conductors or electric valves'connected respectively in the circuits of the windings and so related to the source of alternating current that the periods of conductivity of the several valves or asymmetrical conductors occur dissimultaneously, preferably alternately, whereby the magnetizable member is actuated first by the flux produced by one winding and there.- aiter in opposite dlrection by flux produced by another of the windings.

. My invention resides in a system of the character hereinafter described and claimed.

For an understanding of my invention, reference is to be had to the accompanying drawings, in which:

i Fig. 1 is a diagrammatic view showing my method in which two electron tubes are employed; Fig. 2, a longitudinal section of an electric hammer which is operated by my invention; Fig. 3, a cross-section of Fig. 2

on the line III-III; and Fig. 4, a curve showing the wave forms impressed on the electromagnetic means which operate the reciprocatin elements of an electromagnetic hammer, riveter, drill, or similar tool. Fig. 5 is a diagrammatic view showing my invention applied to a vibratory motor;

Referring first to Fig. 1, 1 and 2 designate alternating current supply lines, across which the rimary winding 3 of the transformer 4 1s connected. The transformer has two secondary windings 5 and 6, the

former being in series with the filament 7 or in efi'ect' a reciprocating magnetic' line 2 to the tube 10 by the wire 12. The

anodes or lates l3 and 14 of the tubes are connected y the wires 15 and 16 to the contacts 17 and 18 of the switch S. The movable COIl'QlCtS 19 and 20 of the switch are insulated from each other and connected respectively to one terminal of the windings 21 and 22, the other terminals being connected by the wires 23 and 24 to the supply lines 2 and 1. The contacts 19 and 20 are carried by the armature 25, retracted by spring 25, which is provided with the operating winding 26, connected to the wire 24 and the fixed contact 27 of the push-button or trigge switch 28, the other fixed contact 29 of the switch being connected to the,

and have shown in Figs. 2 and 3, has been described. Referring to these figures, 32 is a non-magnetic cylinder or barrel in which the magnetic core, armature, or striking element 31 is reciprocable.- The barrel has at one end the external threads 34 and at the other end the internal threads 35, and surrounded by two electromagnets 36 and 37 which have the respective windings 21 and 22 and whose magnetic circuits are separated by the fibre washer 38. The magnets have their magnetic circuits composed partly of the steel casing 39 and partly of L-shaped steel field members 40 arranged radially around the barrel. Each member 40 has a radial arm 41 lying against an end of a winding and an arm 42 lying parallel with the barrel between the latter and awinding. Each magnet has two annular-series of field members with the free ends of the arms 42 of one series facing or opposite the corresponding ends of the other series, these ends being beveled and having lugs or extensions 43 in tel understood after the structure of the electric hammer which I prefer to employ slots in the barrel 32; The outer ends of the arms 41 engage the casing 39.

44 is a cap screwing on the threads 34 and The handle end of the barrel contains the reciprocable hollow core-stop 53 having its outer end closed and having the flange 54 working in the enlarged portion 55 of the.

barrel and limited in its inner movements by the shoulder 56 and in its outer movements by the coiled sprin 57 between the closed ends of the cap an: core-stop. 58 is a setscrew threaded in the handle .and en aging the cap 44 to prevent the accidental oosening of the cap.

59 is a non-magnetic nose piece or cap which'engages the outer end of the casin 39, surrounds the outer end of the barrefi and has a flange 60 abutting against the said end of the barrel. A steel tool bushing 61 extends through the cap59, screws into the threads 35, and has the flange 62 which engages the washer 63 on the end of thecap 59.

64 is a tool, such as a riveting tool, or a drill, having the shank 65 slidable in the tool bushing 61, the tool having a shoulder 66 adapted to engage the bushing when the tool is in its innermost position, as shown in Fig. 2. When in this position the end of the shank projects beyond the inner end of the bushing and lies about opposite the outer circle of lugs 43, preferably about as shown in Fig. 2. course, good results may be had if the end of the tool is not placed precisely as shown.

The parts being assembled as described and shown, ihey may be very closely drawn together by locked by the set-screw 58.

The core 31 is slots 67 to prevent eddy currents.

The operation of the apparatus shownin Figs. 1, 2, and 3 is as follows: Current from .the secondaries 5 and 6 makes the filaments 7. and 9 glow. When the trigger 28 is o era-ted to causethe contact 30 to close t e contacts 27 and 29, current flows from one line, as 2, through the wire 23, the winding- 26 and the wire 24 to the other line, as '1. This current causes the switch S to close, which connects the winding 21 in series with the contacts 19 and 17, the plate 13, the filament 7 and the wire 11, the winding 21 bemg thus connected across the lines 1 and 2. V

Also when the switch S closes, the winding 22 is connected in series with the contacts 20 and 18, the wire 16, the plate 14, the filament turning the cap 44 and securely.

provided with'longitudinal 9 andthe wire 12, the winding 22 being thus connectedacross the lines 1 and 2, but in the reverse order from the connection of the winding 21 to the lines.

Electron tubes of the eneral type shown are well known as recti ers of alternating current. They permit the passage of what is traditionally called positivecurrent and revent the passage of negative current.

hey permit alternations of one sign to pass and suppress alternations of the opposite s1 k ssumin the core 31 to be in the position shown in he drawings and that a positive alternation is supplied to the line 1 and a negative tothe hue 2, current from the line 1 will flow through the electron tube 10 and the winding 22,'but the current from the line 2 will be suppressed by the tube 8, thereby leaving the winding 21 unenergized. Flux generated by the winding 22 pulls the core 31 to the left and causes it to strike the stem 65 of the tool 64. At or about the time the core reaches the limit of its first stroke, which is at about the end of the first half cycle of the alternating current, a positive alternation is impressed on the line 2 and a negative on the line 1. Then positive current flows through the winding 21, but negative current is blocked by the tube 10, thereby causing the winding 22 to be unenerized. Current in the winding 21 generates gux which pulls the core to the right and into contact with the ielding core-stop 53. At about this time, which is at the end 01 the second half cycle, a positive alternation is impressed on the line 1 and a negative on the line 2, whereupon a second cycle of core movements begins, the cycles continuing as .long as the switch S remains closed. The

core 31 reciprocates in synchronism with the consecutive alternations of the current impressed on the lines 1 and 2. The core 31 moves in one direction in substantial syn-. chronism with one alternation of a cycle 01 the impressed current, and in the opposite direction in synchronism with the second alternation of that cycle, and so repeatedly. I do not restrict my invention to any definite number of electron tubes or definite type of electron tubes, but have 'found the tungar to be satisfactory. I do not limit this invention to the useof electron tubes. I have herein adopted the old conception of positive current flowing contrary to the direction of flow of electrons passing from the lighted filament to the plate.

Fig. 4 shows the consecutive wave-forms of positive current impressed on the vwindings 21 and 22 by the a paratus of Fig. 1. In this figure the genera ly sinusoidal curve represents the electro-motive-force im- Due to the asymmetric conductivity of the current impulses indicated at 22, Fig. 4.

These impulses are similarly of greater duterially more thana half cycle, as indicated.

Due to the asymmetric conductivity of the valve 10 and the inductance of its circuit, there traverse the winding 22 the successive ration than a half cycle of the impressed electro-motive-force, and they begin 180 electrical degrees later than the impulses 21, that is, they start at the beginning of the second half of each cycle of the impressed electro-motive-force V. Accordingly, the impulses 21 of one series to some extent overlap, in time, the impulses 22 of the other series. However, the impulses 21 traversing the winding 21 cause successive return movements of the core 31 againstthe back stop 53, and the impulses 22 cause successive forward movements toward the left. against the shank of the tool 64. The frequency of movement or reciprocation of the magnetizable member 31 corresponds with or is dependent upon the frequency of the alternating current source.

In Fig. 5, I show the two windings 21" and 22 arranged on the fields 4:0 at opposite sides of the vibratory armature 31", these features corresponding in the parts 21, 22, and 31, respectively, on Figs. 1 and 2.

The construction and design of the electric hammer that is illustrated in this application is claimed in my co-pendin application relating to electric tools, serial No. 577,720, filed July 26, 1922.-

'This application is a continuation in part.

of my co ending case Serial No. 541,517, filed Marc 6, 1922.

I claim- 1. In a system for reciprocatin electric motors, a reciprocable ma etic e ement, a pair of windings inductive y related to the element so that when one is. energized alone it will cause the element to move in one direction and when the other is energized alone itwill cause the element to move in the opposite direction, alternating current suppliy lines, each containing one of the said win ings and an electronrectifying means in each circuit.

2. In a system for reciprocatin electric motors, a reciprocable magnetic e ement, a pair of windings inductively related to the element so that when one is energized alone it will cause the element to move in one direction and when the other is energized alone it will cause the element to move in the opposite direction, alternating current supply lines, two circuits reversely bridged across the supply lines, each containing one of the said windings, and a two-electrode electron rectifying means in each circuit- 3. In a system for reciprocating electric motors, a reciprocating tool, a winding for operating the same in one direction, an electron rectifier in circuit with the winding, a source of alternating-current connected to the winding and the rectifier and supplying operating current to the said coil, and electron rectifying means for operating the tool in the opposite direction.

4. In a system for reciprocating electric motors, an 'electromagnet, an armature therefor, electronic rectifying means for transmitting current from a source of alternating current to the winding of the electromagnet to move its armature in one direction, a second electromagnet arranged upon energization to movethe armature in the opposite direction, and a second electronic rectifying. means for transmitting to the winding of the second electromagnet the said source. I

5. The combination with an electricallyoperated tool embodying a reciprocating plunger and plural operating windings for actuating said plunger in opposite directions, respectively, of a source of alternating current and means providing two current paths of asymmetrical conductivity connecting said windings to said circuit, respectively, one of said paths being responsive to current waves of one polarity and the other of said paths being responsive to current waves of the other polarit i 6. In a system for electric reciprocating motors, a reciprocating member, a pair of windings which respectively move said member in opposite directions, a source of alternating current for supplying powerproducing current to said windin and thermionic means through which sai source delivers to said windings, respectively, two series of se arate unidirectional im ulses of current 0 different signs, each series of im ulses corresponding with the alternate ha f-waves of current of one "sign of said source, whereby said member reciprocates in synchronism with the current waves. of said source. a

7. The method of operating a reciprocatingmotor provided with a, movable magnetizable member, which comprises selecting from a source of alternating current by asymmetrical electric conduction two series of current impulses, the impulses of one series alternating with those of the, other series, producing magnetic fields by said impulses, and actuating said magnetizable .member in opposite directions by said fields.

8. The method of operating a. reciprocatin motor provided with a. movable magnetremainder of the alternating current from asymmetrical electrical conduction two series I of current impulses, the im ulses of one 'series alternating with an overlapping those of the other series, producing. by the impulses of the difi'erentseries reci roe-ating magnetic flux, and actuating sai magnetizable member in opposite directions by said flux.

9. A reciprocating motor system comprising a reciprocating magnetizable member, a pluralit of windings for producing magnetic fie ds displaced fromeach other along the path of movement of said magnetizable member, for actuating said member in opposite directions, a source of alternating current, and an asymmetrical electrical conductor in circuit with each of said windin s and said source for causing passage of Sn stantially uni-directional current impulses, said as mmetrical electrical conductors being so re ated to said source that the impulses traversing one of said windings alternate with those traversing another of said windlngs.

10. A reciprocating motor system com-.

prising a reciprocating magnetizable memer, a plurality of windings, a source of alternating current, and an asymmetrical electrical conductor in circuit with each of said windings and said source for causing passage of substantially uni-directional current impulses, said asymmetrical electrical conductors being so related to said source that the impulses traversing said windings alternate with each other to produce reciprocating magnetic flux for actuatin said magnetizable member in opposite irections.

11. A reciprocating motor system comgzising a reciprocating magnetlzable memr, a plurality of magnetic field members having air gaps with respect to which said magnetizable member is movable, a plurality of windings 'for energizing said magnetic field members, a source of alternating current, an asymmetricalelectricalconductor in circuit with .each of said windings and said source for causing passage of substantially preponderatingly uni-directional current impulses, said asymmetrical electrical conductors being so related to said source that the impulses traversing said windings move said-magnetizable member in opposite directions past the-positions of mini- -mum length of said air gaps.

12. A reciprocating motor system comrising a reciprocating magnetlzable memer, a.- plurality of windings, a sourceof alternating current, and an asymmetrical electrical conductor in circuit with each of said windings and said source for causing pas-i sage of substantially uni-directional current impulses, said asymmetrical electrical conductors bein so related to said source and to said win mgs that the impulses traversing said windings alternate with and War lap each other to actuate said magnetizable member in opposite directions.

In testimony-whereof I hereunto .afiix my signature this 22nd day of Jul 1922.

- CARL s. W YANDT. 

